Device for imparting an intermittent motion to a perforated filmstrip

ABSTRACT

A drive mechanism or device for imparting intermittent motion to a strip of perforated film or tape, including an oscillating rod having one end thereof pivotably attached to a rotating crank disc about which is supported a profiled cam disc, the other end of the rod having a claw engaging the film perforations and including a member contacting a plane surface on a lever pivoting about an axis extending parallel to the axis of the crank disc, the other end of the lever having a roller engaging the profiled surface of the cam disc so as to impart predetermined axial and longitudinal movements to the claw during each revolution of the crank disc.

United States Patent [191 Beauviala Apr. 23, 1974 DEVICE FOR IMPARTING AN INTERMITTENT MOTION TO A PERFORATED FILMSTRIP [76] Inventor: Jean-Pierre Beauviala, 3 rue Jean [52] US. Cl 226/71, 352/194 [51] Int. Cl. G03b U22 [5 8] Field of Search 226/62-73; 352/194-196 [56] References Cited UNITED STATES PATENTS 2,076,189 4/1937 Wittel 226/71 2,178,243 10/1939 Sachtleben 226/71 2,223,848 12/1940 Falkenhagen.... 226/64 X 2,080,443 5/1937 Sperberg 226/72 1,762,939 6/1930 Wittel...- 226/71 2,749,798 6/1956 Ruhnau 226/65 5 FOREIGN PATENTS OR APPLICATIONS 399,167 3/1963 Switzerland 352/194 Primary Examiner-M. Henson Wood, Jr.

Assistant Examiner-Gene A. Church Attorney, Agent, or Firm-Waters, Roditi, Schwartz & Nissen 5 7 ABSTRACT axis of the crank disc, the other end of the lever having a roller engaging the profiled surface of the cam disc so as to impart predetermined axial and longitudinal movements to the claw during each revolution of the crank disc.

5 Claims, 2 Drawing Figures DEVICE FOR IMPARTING AN INTERMITTENT MOTION TO A PERFORATED FILMSTRIP FIELD OF THE INVENTION The present invention relates to a drive mechanism for imparting intermitten motion to a perforated tape or film strip adapted to effect the sequential positioning of the perforations with respect to a predetermined reference plan, and with a complete absence of operative side noises.

This type of perforated strip intermitten drive mechanism is generally utilized for the printing and reproduction of photograms on a photographic base member or the like which are incorporated in machines required to run in a silent mode.

DISCUSSION OF THE PRIOR ART Intermittent drive mechanisms of this type are presently known which employ the principle of a driving rod and crank-shaft arrangement utilizing a rod with a film drive claw having a longitudinal movement in the direction of film motion, and which is caused by the engagement of a crosshead on a motor drive plate or disc forming an eccentric drive.

The extent of eccentricity of the crosshead with respect to the motor drive disc, in a direction generally perpendicular to the plane of the film, determines the claw actuating course,tand consequently the length of film or tape in response to each revolution of the disc.

In order to obtain a sequence of images on the film it is necessary to always drive the film in the same direction. Accordingly, the claw engages the film perforations during only one-half of each revolution of the motor drive disc.

So. as to effect the foregoing operation, means are provided to impart to the claw an axial motion in synchronism with its longitudinal movement, whereby the claw penetrates the film or tape perforations during only a one-halfrevolution of the drive disc, and is withdrawn from contact therewith during the other half of the drive disc revolution.

In the prior art constructions, the means used to communicate this synchronous axial motion to theclaw requires that a projecting member or knob be fastened to the claw, and adapted to cooperatingly engage acomplex fixed profile cam or alternatively; the claw itself supports this cam so as to maintain it in sliding contact,

during longitudinal movement thereof, against a fixed lug. The prior art devices or mechanisms require a considerable degree of precision in manufacture, since the cam profiles required for silent operation and without wear are difficult to make, and the positioning of the cam with reference to the fixed lug is critical when the instruments are being assembled.

' Devices are also known in which interlocking elements of the shaft crankshaft and drive disc arrangement communicate axial motion to the claw through the intermediary of sliding levers which are responsive to the complex profile cams. These levers are also very difficult to manufacture and moreover do not permit independent axial and longitudinal movements of the claw.

SUMMARY OF THE INVENTION According to the present invention, there is provided a drive mechanism which in a novel manner allows independent motion of the two elementary movements of the claw operation, in effect, of the longitudinal travel and the axial penetration, while constantly assuring the control of these basic motions through the use of uncomplicated profiled mechanical components, which are simply manufactured, and are adapted to move about axes extending parallel to each other.

The device mechanism of the present invention renders it possible to obtain, without requiring high manufacturing or assembling costs, the operating parameters essential to cinematographic production, in effect, noiseless operation, low wear of the film or tape perforations, and excellent positioning of the successive photograms or frames of the film.

The device or mechanism is further distinguished in that the rod which supports the claw is pushed in the direction of film conveyance by a lug which slides along a completely plane surface, locking with a lever having a clearance or position which is imposed by sliding contact, under the pressure of a biasing spring, against a coaxially located cam, and being further adapted to engage with the motor drive disc acting on the springloaded rod. The coaxial cam has its camming surface defined by two successive radial arcs, having a difference in radii which represents as a factor of the amplification of the motion the transmission lever, the amplitude of the axial motion of the claw. All of these movements are effected about axes extending parallel to the axis of the motor drive disc.

BRIEF DESCRIPTION OF THE DRAWING FIG. la illustrates an intermittent motion imparting device, partly in schematic, for a perforated film strip, according to the present invention; and

FIG. 1b is a fragmentary portion of the device shown in FIG. 1a, illustrated on an enlarged scale and in another operative position.

DETAILED DESCRIPTION Referring in detail to the drawing,.the device comprises a motor shaft 1 rotatingly driving a motor drive disc 2 onto which is fastened a crank disc 3 and a circular profile cam 4. Fastened to the crank disc 3 is an end pivot 5 of a crosshead driving rod 19. The extent of eccentricity or offset of the end pivot 5 of the crosshead rod 19 relative to the center of motor shaft 1, can be varied by adjusting the angular position of the crank disc 3 on the drive disc 2. The extent of offset or eccentricity defines the operative motion of the claw to be more fully described.-

The circular profile cam 4 includes two peripheral arcs 6 and 7 of different radii with reference to the center axis of shaft 1, and which are joined by extremely short intermediate slopes 8 and 9. An angle 10 subtended by a radial line passing through slope 8 anda second radial line passing through crosshead pivot 5 depends primarily upon the angular positioning of the profile cam 4 in relation to the motor drive plate 2. The angle 10 makes it possible to adjust the phase of the axial motion of the claw 18 with respect to its longitudinal movement.

A lever 11 extending from a rotatable axle 13 which extends parallel to the motor shaft 1 is provided with a plane surface 12. Accordingly, when the motor shaft 1 is rotated, the lever 11 is subjected to a to-and-fro movement by action of a roller 14 attached to an opposite end thereof and contacted with the circumferential surface of the cam 4 under the biasing force of a spring which is fastened to a support on a frame (not shown).

The plane surface 12 exerts a thrust against a knob 17 which is attached to the claw 18 formed at the upper part of the rod 19 with a spring 16 fastened to the rod constantly biasing the claw 18 toward the surface 12, and with other the spring 15 adapted to be fixed either to the support or to the lever 11.

In lieu of the springs 15 and 16, or possibly supplementing the springs the plane surface 12 on lever 11 and the knob 17 may have inherent or electrically magnetic properties tending to form a magnetic field which may replace or aid the spring 16.

Similarly the roller 14 and the circumferential surface of profile cam 4 may be of a magnetic construction which will assist in maintaining roller 14 in contact with the profile cam.

The mechanism which is the object of the invention makes it possible, therefore, to adjust and control with ease the path of movement of the claw 18 by varying the offset or degree of eccentricity of the crosshead pivot 5 relative to shaft 1 without affecting the extent of axial movement thereof, which is defined only by the difference in the radii of the arcs 6 and 7, and by the length dimensions of the lever 11 with respect to the axle 13 and the position of the knob 17.

The foregoing becomes particularly important in instruments in which it is desirable to change rapidly from a given path of movement to another shorter one, as in apparatuses using both standard 35 mm and techniscope film, in effect, respectivelyfour perforations and two perforations.

The mechanism of the present invention further makes it possible to reduce to a practical minimum the film penetrating movement of the claw l8 and the axial withdrawal thereof from the film perforations,'since the control of this movement phase in relation to the extent of its longitudinal movement is totally independent of adjustment of its amplitude; thereby making it necessary only to loosen profile cam disc 4 from drive disc 2, and to rotate them relative to each other to a predetermined angle at which the phase can be controlled, and than merely to fasten them together without the need of any other adjustment. Consequently, this makes it possible to provide for a perfect extent of claw penetrating motion through the film perforation, while being imbued with completely noiseless running characteristics.

For its moving parts, the mechanism of the present invention utilizes solely easily adjustable components which are centered on parallel axles l and 13, and simple profiled friction or camming surfaces, in effect arcs 6 and 7, and plane surface 12 whose machining and heat treatment presents no difficulties. This ensures that during the critical phase of the longitudinal movement of the film drive, there is no concurrent axial movement; in consequence of which the wear on the film perforations is greatly reduced.

The inventive device forming the noiseless intermittent drive arrangement for the film is well adapted to be used over a large range of film shooting and projection parameters, as well as in the commonly used 24 to 25 frames per second film speed cycles, and furthermore the film drive devicemay be used during forward as well as reverse operations.

Those skilled in the art will be able to employ numerous modifications and variations in the device without exceeding the limitations of the present invention. Thus,the invention is not at all limited only to the particular use and embodiments described and illustrated, which are given only by way of examples. In particular, the invention covers all comparable means constituting equivalent techniques and structures as contemplated and disclosed herein.

What I claim is:

l. A device for imparting intermittent motion to a perforated film, strip or like, comprisingqa crank disc; motor driven shaft means mounting said crank disc and adapted to impart rotation theroto; a cam disc being coaxially supported on said crank disc; said cam disc comprising a circumferential profiled camming surface, said camming surface including two contiguous circular arcs of different radii extending about the rotational axis of said cam disc, said arcs being each interconnected by short slope surface portions so as to afford varied camming action with a minimum degree of acceleration, elongate rod means having one end pivotally connected to said crank disc in offset relationship with said shaft means; film perforation engaging claw means being formed at the other end of said rod means; a lever adapted to oscillate about an axis extending parallel to the axis of said shaft means; said lever having a planar surface formed at one end thereof adapted to be continuously engaged by means on said rod means adjacent said claw means; and roller means being provided at the other end of said lever, said roller means contacting the surface, of said cam disc so as to impart a predetermined pattern of axial and longitudinal movement to said claw means during each revolution of said crank disc.

2. A device as claimed in claim 1, said means on said rod means and said planar surface being magnetizable so as to be mutually attracted upon generation of a magnetic field.

3. A device as claimed in claim 1, said roller means and said cam disc being of magnetizable material so as to be mutually attracted upon generation of a magnetic field.

4. A device as claimed in claim 1, said cam disc being supported on said driven crank disc so as to be angularly adjustable relative thereto about the rotational axis of said discs, said discs being adapted to be interconnected in a plurality of circumferentially varied positions.

5. A device as claimed in claim 1, the pivot end on said rod means fastened to said crank disc being adjustable relative to the rotational axis of said shaft means so as to provide for variation in the extent of said offset from between zero and the radial distance of said crank disc at which said rod means is fastened. 

1. A device for imparting intermittent motion to a perforated film, strip or like, comprising: a crank disc; motor driven shaft means mounting said crank disc and adapted to impart rotation theroto; a cam disc being coaxially supported on said crank disc; said cam disc comprising a circumferential profiled camming surface, said camming surface including two contiguous circular arcs of different radii extending about the rotational axis of said cam disc, said arcs being each inter-connecTed by short slope surface portions so as to afford varied camming action with a minimum degree of acceleration, elongate rod means having one end pivotally connected to said crank disc in offset relationship with said shaft means; film perforation - engaging claw means being formed at the other end of said rod means; a lever adapted to oscillate about an axis extending parallel to the axis of said shaft means; said lever having a planar surface formed at one end thereof adapted to be continuously engaged by means on said rod means adjacent said claw means; and roller means being provided at the other end of said lever, said roller means contacting the surface of said cam disc so as to impart a predetermined pattern of axial and longitudinal movement to said claw means during each revolution of said crank disc.
 2. A device as claimed in claim 1, said means on said rod means and said planar surface being magnetizable so as to be mutually attracted upon generation of a magnetic field.
 3. A device as claimed in claim 1, said roller means and said cam disc being of magnetizable material so as to be mutually attracted upon generation of a magnetic field.
 4. A device as claimed in claim 1, said cam disc being supported on said driven crank disc so as to be angularly adjustable relative thereto about the rotational axis of said discs, said discs being adapted to be interconnected in a plurality of circumferentially varied positions.
 5. A device as claimed in claim 1, the pivot end on said rod means fastened to said crank disc being adjustable relative to the rotational axis of said shaft means so as to provide for variation in the extent of said offset from between zero and the radial distance of said crank disc at which said rod means is fastened. 